Unstacking machine



G. E. VON GAL, JR

Dec. l0, 1963 UNSTACKING MACHINE Filed April 1o, 1959 e sheets-sheet 1" IN V EN TOR.

ATTORNEY GEORGE E. VON GAL,JR.

d BY La Dec. 10, 1963 G. E. voN GAL, JR

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Dec. 10, 1963 G. E. voN GAL, JR 3,113,683

' UNSTACKING MACHINE Filed April 10, 1959 6 Sheets-Sheet 3 ATTORNEY Dec. 10, 1963 G. E. voN GAL, JR 3,113,683

UNSTACKING MACHINE Filed April 10, 1959 6 Sheets-Sheet 4 FI'G. 51

1N V EN TOR.

GEORGE E. VON GAI., JR.

ATTORNEY Dec. 10, 1963 G. E. voN GAI., JR 3,113,683

UNSTACKING MACHINE Filed April l0, 1959 6 Sheets-Sheet 5 1' INVENTOR.

GEORGE E. VON GA| ,JR

ATTORNEY Patented Dec. 10, 1963 3,113,683 UNSTACKlNG MACHINE George E. Von Gal, lr., 3048 Thomas Ave., Montgomery, Ala. Filed Apr. 10, 1959, Ser. No. 805,412 9 Claims. (Cl. 214-35) This invention relates to an unstacking machine and is more particularly concerned with a machine which will automatically and continuously receive consecutive pallets each containing a stack of articles, unload these articles, and pass the unloaded articles in single tile from the machine.

This invention is a continuation-impart of my copending application Serial No. 665,334, filed June 12, 1957, entitled Stacking Machine.

In the past, a few devices have been proposed and built for purpose of unstacking articles. These prior art de vices have usually been extremely expensive and complicated, thus precluding small manufacturers, such as local soft drink bottling plants, from utilizing the same. Fur ther, such prior art devices are not well suited for unstacking crates of bottles and operate at such a low rate as to be impractical for high speed synchronized assembly line use.

in the bottling industries which may utilize unstacking machines, most articles, such as soft drink crates or cases, are reuseable and since such crates do not come in actual contact with the food or liquid to be consumed, they are seldom cleaned prior to being filled, except that such crates are usually inverted to dump the loose dirt and trash therefrom. Therefore, a major problem in the bottling industries is that dirt and other foreign matter from the articles being handled will become lodged in the cogs, gears or other mechanisms of a machine and thereby prevent the proper functioning of the machine or cause the machine to break down.

Briefly, in an attempt to obviate this problem in the prior art and provide an inexpensive yet efficient unstacking machine, I have devised an unstacking machine which includes an elevator adapted to receive successive pallets having bottles in crates in stacked, side by side, relationship. This elevator mechanism lifts the stack of articles in step by step fashion as the opposed slide plates of the unstacking mechanism move toward each other to, in effect, scoop the top layer of articles therefrom. When this top layer is removed by the slide plates, a ram or rake mechanism feeds these articles, still in side by side relationship, to a live conveyor mechanism where the front group of articles are actuated in a path normal to the path of movement of the ram or rake mechanism. This aligns the articles single file in succession along a conveyor, whence the articles proceed to the assembly line for such treatment as desired. As the last layer of articles is removed from the pallet on the elevator mechanism, the elevator mechanism is actuated to lower the empty pallet to its original level where this pallet is removed as a loaded pallet is transferred to take its place. The cycle is then repeated. The unloaded pallet, discharged from the elevator, travels to a magazine assembly Where it is lifted into the magazine to form the lowermost pallet in a stack of pallets.

It will be readily seen that the present unstacking machine is particularly adapted for construction with and operation in conjunction with my stacking machine disclosed in application Serial No. 665,334, tiled lune 12, 1957, now Patent No. 3,056,513, since they are very similar machines and the stacked pallets may be transferred to the stacking machine for use in receiving crates of filled bottles.

Accordingly, it is a primary object of my invention to provide an inexpensive, durable and efficient unstacking machine which is easily manufactured, operated and maintained.

Another object of my invention is to provide an unstacking machine which is well adapted to handle articles, such as crates of empty soft drink bottles, and to unstack these crates from the pallet on which the crates are carried.

Another object of my invention is to provide an unstacking machine in which the stacks of articles to be unstacked need not be uniform in height between respective layers.

Another object of my invention is to provide an unstacking machine having relatively few moving parts to wear out or become out of adjustment.

Another object of my invention is to provide an unstacking machine which is well adapted to operate in conjunction with an assembly line to discharge articles to the assembly line at a substantially constant rate and automatically unstack a succession of pallets in automatic sequence.

Another object of my invention is to provide an un stacking machine which will operate substantially automatically and requires little attention from an operator during this operation.

Another object of my invention is to provide an unstacking machine which will occupy little oor space and which may be installed in processing plants without material alteration to the plant.

Another object of my invention is to provide an automatic stacking machine which will utilize conventional power sources such as compressed air and electricity which are found in most processing plants.

Other and further objects, features and advantages of my invention will become apparent from the following description when taken in conjunction with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views and wherein:

FIG. 1 is a perspective view of a portion of an unstacking machine constructed in accordance with the present invention, parts thereof being broken away to disclose more clearly pertinent parts of the machine.

FIG. 2 is a fragmentary perspective view of the remaining portion of the unstacking machine of FIG. 1 and showing the infeed conveyor which feeds stacked articles on pallets to my unstacking machine.

FIG. 3 is a partially `broken away side elevational view of the unstracking machine disclosed in FIG. 1.

FIG. 4 is `a partially broken away horizontal sectional view taken along lines 44 in FIG. 3.

FlG. 5 is a plan view of a detail of my machine, showing the upper end of the unstacking frame.

FIG. 6 is Ia fragmentary vertical sectional view of the mechanism shown in FIG. 5.

FIG. 7 is a horizontal sectional View taken along lines 7 7 in FIG. 3.

FIG. 8 is a fragmentary end View of the mechanism shown in FIG. 7.

FIG. 9 is fa wiring diagram of the electrical circuit of my unstacking machine.

Referring now -in detail to the embodiment chosen for purpose of illustrating .the present invention, it will be seen that the frame struct-ure of my unstacking machine is made from a plurality of L-beams or angle irons which lare welded or otherwise secured together. This frame comprises a pair of spaced longitudinal 'base -members 10, 10' extending along the floor of a plant and connected at their ends by transverse base members 11, 411 to provide a rectangular base which 4supports the entire remaining structure. Within this base and running transversely thereof are a plurality of reinforcing ribs 12a, 12b, 12e` and 12d which provide support for the various pallet infeed and discharge rollers and belts to be described hereinafter.

On the right portion of the base, as viewed in FIG. 3, and extending upwardly from longitudinal base members 10, 10' are fourr spaced upstanding standards 13a, 13b, 13C and 18d, which define an elevator chute, the upper portion of which is adapted to support the slide plates and the rake or ram mechanism for unloading the stack of articles. For reinforcement, the ends of standards 13a, 13b, 113e and 13d `are joined by an upper rectangular frame comprising top struts 14a, 14b, 14e and 14d.

For reinforcing the |frame struc-ture, I have provided criss-crossed straps 1S on the sides, the straps extending between standards 13a land 13nd and between standards 13b and 113C, as shown in FIG. l. This leaves an open fnont between standards 13a and 13b, between which the loaded pallets are fed to the elevator mechanism.

Pallet Conveying M eclumism Along the lower portion of my unstacking machine is the pallet conveying mechanism, the purpose of which is to convey the loaded pallets to the elevator mechanism and, after the articles have been removed from the pallet, to convey the empty pallet to the magazine mechanism while-.at the same time feeding another loaded pallet to the elevator mechanism. To accomplish this function, i have provided an infeed conveyor, best seen in FG. 2, which includes a plurality of stanchions 16 mounted in front of the base, which stanchions support transverse beams 17 and pallet guide rails v1S. Between the pallet guide -rails 18 and on the transverse beams 17 are two pairs of opposed rol-ler supporting girders 19 which run parallel to each other toward the base of my machine. The inner end of girders 19 are supported from transverse base member 11 by -means of block 20; Between each pair of girders 19 there are provided a plurality of parallel successive infeed rollers `21 which are inclined toward the base of my machine. Several of the transversely aligned rollers 21 at the central portion of the conveyor mechanism are provided `with a pair of side-by-side feed regulating belts 22 which loop around a pair of feed regulating, belt drive )rollers 23 which `are carried on a common axle 24 journalled -by pillow blocks 25.

Inwardly of belts 22 are a pair of aligned idler rollers Z6 and inwardly of the idler rollers 26 are a plurality of elevator feeding rollers 27. The elevator feeding rollers 27 are provided with la pair of elevator feeding belts 28 which extend over these rollers and are driven by a pair of drive rollers 29. The tension of belts 2S is regulated by a pair of tensioning rollers, such as roller 36', which are mounted by means of adjustable brackets 31 on the lower side of -girders 19.

The rollers Z9 are mounted beyond the inner end of girders `19, on a common transverse yshaft 32 which is supported for rotation by spaced pillow blocks 33 mounted at the ends of longitudinal base members 1d, 10'. Between the rollers 29 Aand on shaft 32 is a sprocket 34 driving a chain 35, which, in turn, drives a sprocket of a clutch mechanism 36 on shaft 24. An |upwardly and inwardly projecting clutch :lever 37 between the belts 28 controls the engaging and disengaging of the clutch 36 so that when the lever 37 is 4urged down to a position parallel to the top flights of belts Z8, the clutch 36 will be disengaged such that chain 35 will not rotate axle 24. When lever 37, however, is in the position sho-wn in FIGS. 2 and 3, the clutch 36 is engaged to drive axle 24 and hence to drive through rollers 23, the bel-ts 22.

As best seen in FIG. l, the end of shaft 32 is provided with a drive sprocket 3S which is connected by means of a continuous chain 39 to 1a sprocket 4i) on the end of elevator discharge shaft 41 supported for rotation by pillow 'blocks 42 on longitudinal base members 10, 10. The elevator discharge shaft 41 is provided with a driven sprocket d3 which is driven by means of continuous chain 44, from a drive sprocket 45 on the end of the unloaded pallet positioning shaft 46. Pillow blocks 47 on longitudinal base members 16, -1'0l support the unloaded pallet positioning shaft 46 adjacent standards 13C and 13d.

The driving mechanism for shaft 46 includes an electric infeed conveyor motor 49 which drives a gear reducer 43 mounted on a platform 56 carried by straps 15. A chain S1, driven from a sprocket 52 Ion the gear reducer 48, drives a sprocket 53 on shaft 46. Thus it is seen that upon rotation of -motor 49, shafts '46, 41 and 32, respectively, will be rotated 4synchronously and in the event lever 3'7 is up, as shown in FlG. 2, axle 24 will also be rotated in synchronization with shafts 46, 41 and 32, all being powered from motor 49 by the train of gears, sprockets and chains previously described.

Between shafts 32, and 41 are two pairs of girders 54 which are aligned with girders 19 and are entirely within the space defined by standards 13a, 13b, 13e and 13d, being supported by their ends from ribs 12a and 12b, as best seen in FIG. 3. Between each pair of girders 54 are a plurality of parallel rollers 5S around which are disposed the elevator discharge belts 56, the top flights of which are in alignment -with elevator feeding belts 2S. The rear extreme of belts 56 yloop around drive rollers 57 on shaft `41 and thus thebelts 56 are driven in synchronization with belts 23.

The present embodiment of my machine is particularly adapted to discharge from pallets, layers consisting of six crates of bottles, the crates being arranged two crates wide and three crates deep, the two crate rows being end to end.

The pallets are fed to the infeed conveyor with the three crate row forward so that when received in the frame of my machine there are three crates between the straps 15 and two crates between the fron-t and back of the elevator chute.

The purpose of the -two -lines of -infeed rollers 21 is to facilitate :alignment of the pallet by the guide rails l18. The purpose of the spacing between belts 2-8 is to provide room for the clutch lever 37. The purpose of the spacing between the belts 2S and 56, between respective belts 56 and between belts 738l and shaft 46 is to provide sufficient space to penmit the various members of the elevator to be described hereinafter, to be positioned below the Itop flights of belts 56 vfor receiving and discharging pallets.

The mechanism for feeding the unloaded pallets from the elevator chute :to the magazine chute, where each successive pallet becomes the lowermost pallet of the stack, includes a pair of spaced ysprockets 58 fixed to shaft 46 and aligned respectively with belts 56. A pair of spaced pallet positioning chains 59 extend around these sprockets 5S and around sprockets 6i) on an idler shaft d1, shaft `61 being arranged abovetransverse base member 11. The top flights of chain 59 are slidably carried in channel members 62 appropriately supported by blocks 63 from ribs 12C and 12d.

Centrally of the base and projecting upwardly Within the rear part of the bottom portion of the elevator chute is the lever 170 of limit switches LS9, LS9'a. Adjacent switch L89, LS9a is switch L88.

Elevator Mechanism For lifting each loaded pallet in step-by-step fashion so that the layer removing mechanism to be described hereinafter may remove the topmost layer of crates, I have provided lan elevator frame comprising a pair of spaced parallel transversely extending channel members 70 and 71. The channel member 70 rides between the inner surfaces of standards 13a and 13b and inwardly of its ends, channel member 70 is fixed to a pair of vertical front elevator chains 72 by means of connector plates 73.

The chains 72 are looped around spaced sprockets 74 which are iixed fon shaft 75, the shaft being sup-ported for rotation by pillow blocks 76 ixed to the upper portion of standards 13a and 13b. The end of shaft 75 is provided with a beveled gear 77 which meshes with a complementary beveled gear (not shown) connected to the end of a power transmission shaft 7S, appropriately supported between standards 13b and 13C. As best seen in FIGS. l land 3, a plurality of alignment wheels 79 are provided between sprockets 74 on shaft 75. These alignment wheels 79 are provided with yieldable pneumatic tires 80 around their peripheries. The lower portion of chains 72 loop around idler sprockets, such as sprocket S1, seen in FIG. 3, so that the inner nights of chains 72 remain adjacent and in a parallel veritcal plane with respect to the elevator chute.

Returning now to the elevator platform `or frame, between the central portions of the channel members 70 and 7'1 is a central rib 82 which spaces the channel members 70 and 71 apart suiiiciently that when the elevator frame is in its lowermost position, the channel member 70 passes between belts 2S 'and belts 56 and the channel member 71 passes ybetween belts 56 and chains 59 so as to be below the upper flights lof these belts and chains, the rib 82 resting between the inner girders 54.

Guide brackets 83 lformed from angle irons extend longitudinally between the channel members 70 and 71, these brackets 83 projecting beyond the rear channel member 71 to terminate adjacent standards 13C land 13d respectively. Connectors 84 join the guide brackets 83 to the rear vertical elevator chains 85 so that at all times the elevator frame is in a horizontal position. Chains 85 loop Iaround upper sprockets S6 which are xed to shaft 87, supported for rotation by pillow blocks 88 on standards 13C and 13d. The end of shaft 87 is provided with a beveled gear (not shown) which meshes with a beveled gear (not shown) on the end of shaft 78. Thus, shafts 75 land 87 rotate together in opposite directions upon r0- tation of shaft 78. The lower portion of chains 85 loop around idler sprockets, such `as idler sprocket 89 as shown in FIG. 3.

To actuate the elevator mechanism, I have provided an elevator motor 92 having a gear reducer 93 on a platform 94 supported by straps 95 between standards 13b and 13e. A sprocket 96 driven from -gear reducer 93 drives through chain 97 a sprocket 98 on drive shaft 7S. Thus, upon rotation of motor 92 in ione direction, the elevator frame will be lifted by chains 72 and S5 and upon rotation of motor 92 in the other direction, the elevator frame will be lowered.

To guide the cases on each incoming pallet between standards 13a and 13b, I have provided guards 99 which are secured to standards 13a and 13b. These guards 99 are formed of long flat sheets of metal which extend forwardly then loutwardly :around the inner and front sides of chains 72.

Top Layer Removing Mechanism IFor removing the top layer of crates, I have provided a top layer removing mechanism at the upper portion of standards 13a, 13b, 13e and 13d, this mechanism being best seen in FIGS. 4, 5 and 6. 'Ihe function of the top layer removing mechanism is to scoop the top layer of crates by means of the tines from the layers therebelow and support this layer in its l.assembled fashion on plates so that the rake mechanism urges the layer from the plates t-o a live conveyor whence the forward crates are urged in a path normal to the path of travel of the rams lor rakes. 'Ilo laccomplish this function, I have provided a pair of opposed rectangular slide plates 100 and 100 which are movable toward and away from each other in a horizontal plane in the upper part of the frame structure. Each of the plates 100 and 100 is provided with a pair of parallel `sleeves 101 `and 102 secured to the lower surface thereof, so as to be aligned longitudinally with their complementary sleeves. A pair of spaced parallel longitudinally extending rods 103 and '104 which pass adjacent standards 13d and 13a and adjacent standards 13e and 13b, respectively, receive the sleeves 101 and 102'. These rods 103 Aand 104 are fixed at their ends, outwardly of the elevator chute, to transverse rod supporting struts 105 and 106. The forward strut 105 is, in turn, supported by its ends, by means of a pair of spaced brackets '107, 107 projecting forwardly from the standards `13a and 13b. Thus is formed a U-shaped platte supporting frame, the brackets 107 |and 107 which are of sufficient length that the forward plate 100 may be retracted along rods 103 and 104 to lie completely outside the chute Iformed by standards 13a, 13b, 13C and 13d.

At the rear of my machine, as viewed in FIG. 4, the rear strut 106 is supported in spaced relationship to the elevator frame by -a discharge roller supporting girder 10S to which ione end of strut 106 is connected and a standard 110951 of the pallet magazine, there being a short bracket 110 extending from the standard 10941 to the end of strut 106.

It is now seen that both slide plates 100 and 100 are slidably supported in -a horizontal plane for movement toward and away from each other. As viewed in FIG. 4, the solid line representation indicates the plates 100 and 100' in the yopen position and the broken line representation indicates the plates y100 and 100 in the closed position.

For moving plates 100 and 100 from the opened to the closed position, I have provided a pair of dou-ble acting air cylinders .i111 and 112 connected respectively to the struts 105 and 106. The cylinders 111 and 112 are provided with the usual pistons (not shown) from 'which project piston rods 113 and 114, the rods being secured to the bottom surfaces of plates 100 and 100 by blocks -115 and V116 so that when air -acts against the outer surfaces of the pistons (not shown), fthe plates 100` and 100" will be urged to their closed position `and when air acts upon the inner surface of these pistons, the plates 100 and 100" will be urged to their open position. As is seen in FIGS. 3 and 4, the cylinder 11-1 is supported by a brace 117 extending from strut 105.

The valves of air cylinders 111 and 112 are operated by solenoids SVl, SV1 and SVZ, SVZ'; the solenoids SVI, SVI being for operating the valves to admit air to both cylinders 111, 112 for opening slide plates 100, 100 and the solenoids SV2, SVZ' being for operating the valves to admit air to both cylinders 111, 112 for closing the slide plates 100, 100.

Along the inner edges of the plates 100 and 100" are respectively a plurality of opposed and aligned, inwardly and downwardly projecting tines 118 and 119, the points of which are in close proximity when the slide plates 100 and 100 are in their closed position. The spaces between adjacent tines 1.18 and 119 are such that upon closing of slide plates 100 and 100', the tines 11S and 119I will pass between adjacent bottles in the crates of the second uppermost layer of crates, as will be described more fully hereinafter.

For acting in conjunction with the tires `80 in urging the upper layer of crates into a compact group, the sides of the crates abutting each other, I have provided along the rear portion of the elevator chute, upwardly and in wardly inclined guide struts 121i, 12d termina-ting opposite tires 89 with a guide plate member having an inclined section 121 and a vertical section 122.

In the same horizontal plane with the tires 8l? and the: guide plate member are additional opposed complementary guide plate members lat the opposite sides of the elevator chute. The construction of each of the opposed guide plate member is identical and hence only one is. illustrated in FIG. l. This guide plate member includes. a vertical plate section 131 which is supported inwardly` of the plane of standards 13a and 13d by a coiled spring 131. A strap 132 located centrally between two parallel horizontal beams 133 and 134 extending between standards 13a and 13d supports spring 131. Connected from the bottom edge of plate 131 by a piano hinge 133" is an inclined plate which is normally inclined slightly downwardly and outwardly. The complementary guide members urge each layer of crates transversely into a compact layer as the layer is raised therebetween by the elevator.

The channel 135 illustrated in the drawings is for the purpose of supporting appropriate electrical cables and air conduits which are not illustrated.

Mounted slightly above the plane of slide plates 161i and 13d at the front and rear of the elevator chute are the alignment bars 136 and 136 extending respectively between standards 13a and 13b and between standards 13e and 13d, The purpose of the alignment bars 136 and 136 is to retain a layer of crates on the slide plates th and 160' within the contines of the elevator chute.

Ram Mechanism Above the slide plates 1li() and 101i is a ram mechanism, the function of which is to urge the layer of crates on the slide plates 1131i and 160" from the chute dened by standards 13a, 13b, 13C and 13d to the discharge conveyor. This ram mechanism is best seen in FIGS. 5 and 6.

in more detail, the ram mechanism includes a reversible rake motor 140 which drives a gear lreducer 142 mounted on platform 141. The gear reducer 142, in turn, drives by means of sprocket 143 a continuous chain 144 arranged over a sprocket 145 driving through slip clutch 145 a power shaft 146.

Power shaft 146 is jour-nalled for rotation by a pair of spaced pillow blocks 147 and 147" mounted respectively on top struts 14a and 140 above standards 13b and 13C. Between the pillow blocks 147 and 147 fixed on shaft 146 `are a pair of spaced sprockets 148 and 148' which are provided with continuous chains 149 and 149 driving sprockets 150 and 15d on an idler shaft 151 carried by pillow blocks 152 and 152. The pillow blocks 152, 152 are mounted at the opposite ends of top struts 14a and 14e from pillow blocks 147 and 147 so that the chains 149 and 149 extend across the upper end of the elevator chute.

The rake supporting structure comprises a pair of slide blocks 160 and 160 connected respectively to chains 149 .and 14.9. The slide blocks 161B and 160" are slidably carried by a pair of transverse rods 161 and 161' which respectively lie beneath and parallel to the lower flights of chains 149 and 142/, the transverse rods 161 and 161 being supported by their ends by top struts 14h and 14d. Extending between the slide blocks 16@ and 161i' is a traveler frame having travelers 162, 1612. A pair of spaced rake arms 163K, 163 are suspended from spaced tie rods 164 and 164 xed to the travelers 162 and 162', the rake arms 163 'and 163' extending down therefrom to terminate above the plane of slide plates 100 and 1% so as to 4be respectively on about a transverse center line of plates 100 and 100 when the plates 1110 and 105) are closed. At the ends of rake arms 163 and 163 the rakes 16S and 165 extend longitudinally of the machine across the closed slide plates and 100' so as to engage the side of crates of bottles on the slide plates 104) and 100'. Usually the rakes 165 and 165' are slightly less wide than a crate of bottles so that the spaced pair of pusher fingers 166 on each of the rakes and 165 will engage the'crate at one side thereof and adjacent the corners of the crate to thereby compensate for irregularities in the surface of the side of the crate and aifording an even push.

Mounted on the top of the front traveler 162 is a switch engaging lug 167 which, when the rake assembly traverses the slide plates 11H1` .and 10d', engages switches L84, 1.84@ mounted, as shown in FIGS. 5 and 6, on the inside of top strut 1411. 'Ihe switch L54 is electrically connected to the motor 140 for reversing the same, as will be pointed out hereinafter. Mounted on alignment bar 135, adjacent standard 13b is switch LS1 for detecting the presence of the crates on the slide plates 1611, 100.

Discharge Conveyor The purpose of the discharge conveyor is to receive successive pairs of crates urged by the rake mechanism from the slide plates 1G11 and 108 and to feed these crated longitudinally in single tile out of my machine.

As best seen in FIG. 4, the discharge rollers are carried by axles 181 which are journalled by roller supporting girder 10S and a second roller supporting girder 10S outward-ly and parallel to girder 1198. Each of rollers 180 ris .a live roller, being actuated by sprockets 1'82 on the outer ends of axles 181. The sprockets 182 are driven by a continuous chain 183 looped around the outermost sprockets 182 so that the top flight of chain 183 engages all sprockets 182.

As seen in FIG. 3, the endmost axle 181 protrudes beyond girder 168 and is provided with a second sprocket 184 which is driven by chain 185 from sprocket 186 on gear reducer 187. The discharge motor 188 actuates gear reducer 187, the gear reducer being mounted on platform 189 on a longitudinally extending reinforcing runner 190 which extends between standards 1691; and 1091: of the magazine chute.

A suitable cover 191 may be provided over chain 183 and sprockets 182.

As best seen in FIGS. 3 and4, a pair of coaxially aligned discharge rollers 192 and 192 are provided between the side edges of the closed slide plates 100x and 1119 respectively and the girder 108. These rollers `192 and 192' are fixed on a longitudinally extending drive shaft 193 journalled by standards 13b and 13C. The peripheries of rollers 192 and 1921 have a rough surface, such as splined rubber, the upper extremities of which are slightly above the plane of the slide plates ltltrand 1110 and rollers 180 so that as the crates are urged outwardly onto the discharge rollers 130, the crates will ride over the upper peripheries of rollers 192 and 1-92 and will thereby be fed at an accelerated rate to the dis'- charge rollers 108. The end of shaft 1%` is provided with a beveled gear 194 meshing with a beveled gear 195 on a vertically disposed shaft 196. The shaft-19,6 is journalled by a bracket 197 in a cut away portion of standard 13C. Fixed on shaft 196 is a wheel 198 having a rubber periphery protruding inwardly beyond the end of alignment bar 136', and outwardly over a portion of rollers 180, so as to Contact the rearmost side of the crates as they are discharged by the rake mechanismv and a side of each crate as `it is discharged by rollers 180. It is now seen that the wheel 198 and rollers 192, 192' are so geared -together as to rotate in unison, each acting against a portion of the crates being discharged onto rollers 180.

In FIG. 4 it will be seen that wheel 198 and rollers 192, 192' are driven at a higher peripheral speed than the speed of travel of rakes 165, 16S by means of a bevel gear 199 on the end of one of shafts 1181, the bevel gear 199 meshing with bevel gear 195. About opposite wheel 9 198 is switch LS2 which indica-tes when the discharge conveyor is free to receive additional crates.

At the end of girders 10S and 10S' is an inclined discharge ramp denoted generally by numeral 199. The single file crates are fed by rollers 180 to this ramp which feeds the crates from my machine.

Pallet Stacking M eclzanism At the rear of my machine is a pallet stacking magazine mechanism, the function of which is to receive and store the unloaded pallets discharged from the elevator frame. To accomplish this function, I have provided a vertical pallet magazine parallel to and spaced from the elevator chute. This pallet magazine is dened by four upright standards 10911, 10911, 109C and 10911', the standards 109C and 10911 being at the rear corners of the base and standards 10911 and 10911 being adjacent standards 13d and 13C on longitudinal base members 10 and 10. The standard 1091i is shorter than the other standards.

Below the reinforcing runner 190 there are a plurality of additional parallel reinforcing runners, including runner 19011, 19011, 190C and 1901i spaced parallel one below the other between an intermediate portion of standard 10911 and the upper end of standard 1091i. Reinforcing runners 20011, 20011 and 20011 extend between standards 10911 and 1091i and are parallel to the reinforcing runners of standards 10911 and 109C. Mounted outwardly to the runners 190 and 190C is a panel 201 which projects from the frame structure and contains the electrical equipment such as relays and the like.

Depending from the central portions of runners 19011 and 20011 respectively are a pair of air cylinders 20211 and 20211 which contain the usual pistons for actuating the downwardly projecting piston rods 20311 and 20317. Carried by the lower ends of these piston rods 20311 and 203b are a pair of opposed horizontal lift beams 20411 and 20417 which slide along the inner surfaces of upstanding slide bars 205 and 206, the slide bars 206 extending from longitudinal base member 10 upwardly and outwardly in spaced parallel relationship and being supported at intermediate points by runner 2001i. Similarly, slide bars 205 are carried by longitudinal base member 10 and runner 19051' and extend upwardly and outwardly.

As best seen in FIG. 7 and 8, lift arms 20711 and 20711 project inwardly and slightly upwardly from lift beams 20411 and 2045, respectively. The ends of these lift arms 207'11 and 2071 carry the lift plates 20811 and 20Sb, best seen in FIG. 7. The lift plates 20811, 20315 are arranged in about a horizontal plane normally below the plane of the upper iiignts of chains 59 and spaced apart sufficiently that the edges of a pallet carried by chains 59 into the pallet magazine will overlie plates 20811 and 20811. Thus, upon the simultaneous actuation of cylinders 20211 and 20211, and the resulting upward movement of rods 20311 and 2031), the plates 20311 and 20817 will lift the pallet from chains 59 upwardly by a distance equal to the distance of travel of rods 20311 and 20311.

On transverse base member 11 are a pair of stop members denoter generally by numeral 209 which stand above the plane of the upper flights of chain 59 and limit the inward movement of a pallet carried on chains 59. Immediately ahead of the stop members 209 in the path of travel of the pallet is a switch arm 210 which actuates a swtich LS10 on a cross member 212 centrally between base member 11 and rib 12d. The purpose of switch LS10 is to actuate the air cylinders 20211 and 202b. The valves of air cylinders 20251, 202!) are provided with solenoids SV3, SV3 and SV4, SVl. Solenoids SV3, SVS position the valves for retracting piston rods 20311, 20311 and solenoids SVd, SV4 position the valves for extending piston rods 2030, 20311.

For supporting the stack of pallets to be stacked in the pallet magazine, I have provided a pallet engaging mechanism having fingers 220 and 220 which project between the upper and lower boards of the lowermost pallet, the fingers 220 and 220' being adapted to be urged outwardly as each additional pallet is thrust upwardly and thereafter to spring inwardly beneath the edges of that additional pallet. The pallet engaging mechanism, as best seen in FIGS. 7 and 8, includes pairs of opposed rocker arms 22111, 22111, 221C and 221d pivotally mounted by pivot pins 22211, 222b, 222C and 222d to the lower portion of standards 10911, 10911, 109C and 10911 respectively. These rocker arms project upwardly, outwardly adjacent standards 109C and 1091i, the upper ends of rocker arms 22111 and 221b being joined by a linger carrying bar 223 and the upper ends of rocker arms 221C and 221:1 being joined by finger carrying bar 223'. The lingers 220 and 220 project horizontally inwardly from bars 223 and 223' respectively, terminating within the pallet magazine. Angling downwardly and outwardly from the ends of fingers 220 and 220 respectively are the camming bars 224 and 224 against which the front and back edges of the pallet, as it is lifted by plates 20811 and 208b, act to pivot the pallet engaging mechanism outwardly.

Springs 22511, 22517, 225e and 22511' connected respectively from intermediate portions of rocker arms 22111, 2211), 221C and 22111 to the base members 10 and 10 resiliently resist outward movement and urge the rocker arms inwardly; the inward movement of the rocker arms, however, is limited by standards 10911, 109b, 109e and 1091i. The outward movement of the rocker arms is limited by the diagonally opposed hook members 226 and 226 which are supported by standards 10911 and 1091i and pass outwardly and behind rocker arms 22111 and 2211i.

As best seen in FIGS. 1 and 2, an accumulator tank 230 is provided to supply iluid, preferably air under pressure, to the various pneumatic cylinders such as cylinders 111, 112 and cylinders 20211 and 202b. The tubing to and from the accumulator tank is not shown for purpose of clarity. It will be understood, however, that cylinders 111 and 112 are double acting and that appropriate electrically controlled valves regulate the actuation of the piston of these cylinders. The cylinders 20211 and 202b may have single acting, spring return pistons since positive actuation of piston rods 20311 and 20311 is not required. Appropriate electrical valves control the ow of fluid from the accumulator tank 230 to the cylinders 20211 and 20211.

Electrical Circuits I n FIG. 9 the wiring diagram of the present invention is illustrated. Here, line current either 110 volts or 220 volts is supplied from lines L1, L2 to motors 140, 92, 49 and 188, relays M1 and M2 controlling motor 140, relays M3 and M4 controlling motor 92, relay M5 controlling motor 49 and relay M6 controlling motor 188. Line current is also supplied to transformer T where it is converted to 12 volts, one lead from the secondary coil of transformer T being grounded through several series connected normally closed switches MSI, MS2, MS3 and M84. Switches M81, MS2, MSS and MS4 are motor heater circuit breakers connected respectively to motors 140, 92, 49 and 188. From the hot side of the transformer T, conductor 300 leads through fuse F to a three position main switch SSI which is adapted to throw current selectively to auxiliary bus 301 or main bus 302 or to be positioned in the olf position, as shown in FIG. 9.

Incidental to the circuit is a glow light GL which leads from conductor 300 to the ground bus 303 which thence leads to ground. With current being supplied through transformer T and provided switches M81, MS2, M53 and M84 are closed and the fuse F is good, glow light GL will light indicating power to the electrical system.

Between buses 302 and 303 are the rake forward controls consisting of wire 304 leading from bus 302 through switches 1.515 and LS17 in parallel and thence through switches R1-4, LS1, LS411 and M2-2 in series, through relay M1 to ground bus 303. Switch R1-4 is normally open and the other switches in series therewith 11 are normally closed. Switch LS3 and LS18, in series with each other, are in parallel with switch R1-4 and `switch LS2 is an parallel with switch LS1. When a circuit is made to relay M1, motor 140 rotates in a direction to drive the rakes 165, 165' across the elevator chute.

Below wire 304 in FIG. 9 are the rake return controls, comprising wire 305 which supplies current from Vbus 302 through switches LS4, LSS and M1-2 to relay M2 and .thence to ground bus 303. Switches LSS and M1-2 are normally closed and switch LS4 .is normally open. In series with each other are a normally open switch M2-1 and a normally closed switch PB1 which are in parallel with switch L54.

For independent return of the rake, switches PE1, FB2 and BB3 are provided. Switches PBl and BB3 operate together so that when switch PBI is closed, switch PB3 is open and vice versa. Wires 306 and 307 lead from buses 301 and 302 respectively to switches PB3 and PBZ and from switches FB2 and PB3 wire 308 leads to wire 305 between switch LS4 and LSS.

A cross connect wire 309 leading from wire 305 between switches LSS and M1-2 and is connected to wires 310 and 311, wire 310 leading through relay R3 to ground bus 303. Wire 311 is connected through normally closed switch PB4 to one external terminal of a selector switch PBS, the other external terminal of which is connected through wire 312 to bus 301. The central terminal of switch vPBS is connected via wire 313 through parallel connected valve control solenoids SVZ and SVZ to ground. Solenoids SV2 and SV2 control the actuation of air cylinders 201 and 202 respectively.

Switch PE4 is normally closed and is operated in conjunction with switches PE1 and BB3 so that switch PB4 is closed when switch PB1 is closed and switch BB3 is opened; conversely switch BB3 is closed and switch PE1 is open.

The next two circuit include the elevator up controls and the elevator down controls. In the elevator up circuit, wire 314 leads from bus 302 through a pair of parallel switches LS12 and RS-l, through a pair of parallel switches LS13 and LSH, through a pair of parallel switches R2-3 and MES-1 to switch LSSa. Switch LSSa is connected in series through switches R1-2 and M4-2, and through relay M3 to ground. Switches LS12, LS13, LS14, M3-1 and LSSa are normally open and switches R-1, R2-3, R1-'2 and M4-2 are normally closed. Jumping the switches R2-3, M3-1, LSSa and R1-2 is a bypass wire 315 which has series connected normally open switches R4-1 and L59.

The elevator down circuit includes wire 316 connected through relay M4 from bus 302 to bus 303. Switches R22, R1-1, R34, M1-1 and M3-3 are in series along wire 316. Switches R2-2, M1-1 and M3-3 are normally closed and switches R1-1 and R3-1 are normally open. Jumping switches R1-1 and R3-1 is a wire 317 having therein a normally opened switch M41. Leading from wire 301 and connecting to wire 316 between switches M1-1 and the other switches of that circuit is wire 31S having two series connected switches LSSa and PB6. Switch LSSa is normally closed and switch P136 is normally opened. Relays M3 and M4 are connected to motor 92. When relay M3 is energized, current is supplied to actuate motor 92 to raise the elevator and when relay M4 is energized current is supplied to motor 92 to lower the elevator.

The next circuit includes the infeed conveyor thereof. Relay M5 thereof actuates motor 49 which is adapted to rotate in only one direction. A wire 319 leads from bus 302 to ground bus 303, through relay M5, the wire 319 having in series therein switches LS19, LS20, R2-1 and M32. Switches LS19, LS20 and M3-2 are normally closed and switch R2-1 is normally opened.

In the next circuit are the discharge conveyor controls. Motor 188 is controlled by relay M6 which is connected by wire 320 between buses 302 and 303, the

wire 320 having therein an on-oi push button switch SSZ.

In the next circuit are the slide plate closed controls, including wire 321 which connects solenoids SVI, SVI' to bus 302 through series connected switches LS12, R5-2, R1-3 and LS3. Switches LS12, R1-3 and LS3 are normally closed and switch R5-2 is normally open. Solenoids SV1 and SVI operate the valves of air cylinders 111, 112 for opening slide plates 100, 100.

In the circuit of wire 322 are the pallet up controls, wherein normally opened switch LS1@ and solenoids SV3, SVS are connected in series between bus 302 and ground. As pointed out above, solenoids SV3, SVS', when energized, actuate the valves of air cylinders 202:1, 202b to cause retraction of piston rods 203a, 20312. To return the retracted piston rods 203m, 20317, solenoids SV4 and SV4' are provided in connection with the valves of air cylinders 202e and 202b. Solenoids SV4 and SV4 are connected between bus 302 and ground by wire 323, having normally opened switch LS11 in series therein. Several relays are provided in any event. The coil of relay R1 is energized by the closing of normally open switch LS7 which supplies, via wire 324, current from bus 302 through relay R1 to ground bus 303. Relay R1 controls switches R1-1, R1-2, R1-3 and R14.

The coil of relay R2 is energized by the closing of switch LS3, connected in series with relay R2 by wire 325 leading from bus 302 to bus 303. Relay R2 controls switches R2-1, R2-2, R2-3 and R2-4.

The coil of relay R4 is connected through wire 326 between buses 302 and 303, having series connected switches L89 and R2-4 therein. Switch LS9 is normally closed and switch R2-4 is normally opened. Between wires 325 and 326 is a cross-connect wire 327 having series switches R5-3 and R4-2. Wire 327 connects to wire 325 between switch LSS and relay R2 and connects to wire 326 between R2-4 and relay R4. Switch R5-3 is normally closed and switch R41-2 is normally opened.

Relay R5 is connected by wire 328 to a selector switch SS3 which is adapted to selectively connect relay R5 between buses 302 and 303 through switches LSG and LS15 respectively.

Relay R4 controls switches R4-1 and R41-2; relay R5 controls switches RS-l, RS-Z and R5-3.

Referring again to the relays R3, M1, M2, M3 and M4, it will be understood that relay R3 controls switch R3-1; relay M1 controls switches M1-1and M1-2; relay M2 controls switches M2-1 and M2-2; relay M3 controls switches M3-1, M3-2 and N13-3; and relay M4 controls switches M4-1 and M4-2.

1t will also be understood that the term LS applied to the various switches means limit switch; the term SS means selector switch and the term R refers to relays, while the term M refers to motor control relays.

Limit Switch Location Ln the drawings it will be seen that switch LS1 is positioned on alignment bar 136 to detect the presence of crates on the side plates 100, at a position adjacent rollers 192, 192. Switch LSZ is positioned on girder 10S in alignment with standards 13e and 13d so as to indicate when the rollers adjacent rollers 192, 192 are free of crates and may receive additional crates.

Switches LS3 and LS18 are positioned on the beam 133 so as to be engaged respectively by the slide plates 100, 100' when they are completely closed.

As seen in FIG. 5, switches LS4, LS4a are mounted on top strut 14b for engagement by switch engaging lug 167 on traveler 162 when the rakes 165, 165' are completely forward. Switch LSS, LSSa are carried by a brace 169 extending inwardly from top strut 14d for engagement by traveler 162' when the rakes 165, 165 are completely returned.

Switches L86 and LS15 are mounted on an upstanding brace 163 which is secured to an intermediate portion or" alignment bar 136', the switch LS15 being mount- 13 ed above switch LS6. The switches LS6 and LSlS have switch arms which extend into the elevator chute at preselected heights so as to be engaged by the tops of the bottles in the uppermost crate or the top of the uppermost crate itself.

Switch LS7 is mounted on alignment bar 136 so as to be engaged by channel member 71 on the elevator but not by any crates or the pallet, the switch arm of switch LS7 terminating slightly above the upper plane of the slide plates 100, 100.

Switches LSS, LSSa, L89, LS9a, LSll` and LS11 are best seen in FIGS. 7 and 8. Switches LSS, LSSa are carried by rib 12e in a position to be engaged by the elevator when it is in its lowermost position. Switches LS9, LS9a are centrally of the base adjacent the center of nib LS12c. The switch arm 170 operating switches L89, LS9a projects upwardly and forwardly into the bottom portion of the elevator chute so as to be engaged by each loaded pallet ias it is about properly positioned on the elevator.

Switch LSlt) is centrally on cross member 212 and its switch arm 210 is in a position to be engaged by an unloaded pallet as it is about properly positioned for lifting by lift plates 2t8a, 208i). Switch LS11 is located on standard 109er and has an arm adapted to be engaged by lift beam Ztl-4a when piston rod 20'3a cornpletes its upward travel.

Switches LS12, LSlZa, as seen in FIG. 3, are carried by standard 13b with their common switch arm extending into the path of travel of Athe pallet in the chute so as to be engaged by the pallet in a plane immediately below the plane of slide plates 19t), 196.

Switches LS13 and 1.514, as seen in LFIG. 4, are carried on the inner surfaces of struts S and 106 respectively. These switches LS13 and LS14 are in position to be engaged by slide plates 1%, 161) respectively when they are completely opened.

Switches LS16 and LS17 are positioned at any convenient place along the path of discharge of the crates to indicate when additional crates are needed in the production line.

Switch LS19 is positioned as lshown in FIG. 3 to be engaged by lthe crates on a loaded pallet as the pallet is positioned on the elevator.

Switch LSZ is carried centrally on the bottom edge of strut 106 so as to be engaged by the top pallet in the pallet magazine when the magazine is lled.

Operation From the foregoing description the operation of my unloading machine is apparent. The pallet which the present embodiment is adapted to unload is a pallet having a plurality of layers of crates of bottles, six crates to the layer. The pallet is of a size to provide space for a layer two crates deep and three crates across.

The pallets -so loaded are fed one after another down the rollers 21 in FIG. 2. Since rollers 21 are free rolling, the loaded pallets pass therealong until the tirst pallet reaches feed regulating belt 22. It is important that the pallets be fed with a three crate side first into my machine. Prior to automatic operation, the elevator must be arranged in the down position, the rakes 165, 16S in the completely returned position, and the slide plates 166, 100 in their opened position. To accomplish this in the event the elements are not positioned, switch SS1 of FIG. 9 is thrown from its ott position to its auxiliary position, supplying current from wire 3G() to the auxiliary bus 301.

To return the elevator to the bottom independently, the operator depresses switch PB6 which supplies current from auxiliary bus 301 through limit switch LSa, wire 313, wire 316, lswitch yM1-1 and switch M3-3 to relay M4. Upon the energization of relay M4, motor 92 is actuated to bring the elevator down until it strikes limit switch LSSa (seen in FIG. 7), opening it and thereby 14 deenergizing the circuit. The elevator fully down, closes switch LSS for automatic operation.

To open the slide plates 1%, 109', the operator depresses switch PBS 'which supplies current from bus 301 through wires 312 and 313 to solenoids SVZ and SV2. It will be understood that while one side of switch PBS is closed the other side is opened and hence no current will be supplied through wire 311 at this time. With the slide plates 100, 190 open, switches LS13 and LS14 (seen in FIG. 4) are closed.

To return the rakes 165, 165 to the position shown in FIG. l, the operator depresses the push button, closing switch P133 which supplies current from auxiliary bus 3M, through 'wire 3136, Wire SGS, wire 305, switch LSS and M1-2 to energize relay M2 and thus energize motor `for rotation in the proper direction. Since push buttons PB1, PBS and PE4 are operated simultaneously, no current will be supplied the main bu-s 302 via the holddown switch -M2-1 since switch PBI is open. lFurther, no current will be supplied to actuate the slide plates 1GO, 100 since switch PE4 yis open. When the fakes are in the completely returned position, traveler 162 strikes and opens switch LSS, thereby breaking the circuit to relay M2 which results in deenergizing motor 140.

For automatic operation, tirst, selector switch SS?,y is positioned either in the up or down position according to the size of bottles in the crates. In the present embodiment, if the crates on the pallets contain 6 ounce bottles, the selector switch SS3 is positioned up, activating switch L56 (seen in FIGS. 5 and 6). If, on the other hand, the crates contain larger bottles, such as l2 ounce bottles, selector switch SSS is positioned down so as to activate switch LS15 (seen in FIGS. 5 and v6). Assume for the purpose of this description that the standard 6 ounce soft drink bottle is contained in the crates on the pallet; in such case, selecto-r switch SSS is placed in the position shown in FIG. 9. Next, the switch SS1 is depressed past the off position as shown in FIG. 1 to the automatic position supplying current from 'wire Sil@ to the main bus 382.

Next the selector switch SS2 is placed in the depressed position thereby supplying current from bus 302, via wire 320 to energize relay M6 which in turn energizes motor V188 to cause rotation of lrollers 18th With the elevator down, limit switch LSS is closed and hence relay R2 is energized. Relay R2, in turn, closes switch R2-1 of wire 319, opens switch R2-2 of wire 316, opens R12-3 of Iwire 314 and closes R2-4 of wire 326. The closing of switch R2-1 supplies current via switches LS19, LS20, M3-2 (which are normally closed) to relay MS which energizes motor 49 and drives the infeed conveyors, namely belts 23, 2S and 56 as well as chains 59.

With the closing of switch R2-4, current is supplied through switch LS9a and wire 326 to relay R4. The energization of relay R4 closes switches R4-1 of wire 315 and R11-2 of wire 327. Thus, regardless of the position of switch LS9a and R2-4, current will be supplied to relay R4 via wires 325 and 327 so long as the elevator is down, closing switch LSS and provided switch LSG is not closed.

As the rst pallet is -fed toward the elevator chute, it trips clutch lever 37, thereby disengaging rollers 23 yand momentarily stopping the movement of all except the irst evaded pallet toward the elevator chute. This provides a space between each successive pallet.

As the first pallet enters the elevator chute, and is positioned over the elevator, `it engages switches LS9, LS9a, closing switch L89` and opening switch LS9a. Switch LS9a is operably connected to switch L89 and hence is `opened -upon the closing of switch LS9.

'It is to be remembered that switches LS13 and LS14 are closed. Thus, upon the closing of switch LS9, current is supplied from bus 302 via wire 314, switch R5-1,

l switches LS13 or LS14, switch R4-1, LS9, wire 315 and switch M4-2 to relay M3 which energized motor 92 to lift the loaded pallet. The energization of relay M3 opens switch yM3-2 and thereby deenergizes relay M5 and turns oft infeed conveyor motor 49. Thus, no additional pallets will feed to the elevator.

When the top layer of crates is carried upwardly by the elevator, it engages and closes switch L56 (if the taller 12 ounce bottle crates were being unstacked, switch LS would be the switch to be engaged). This energizes relay R5-1, R5.13 and closes switch R5-2. The opening of switch R5-1 opens the circuit to relay M3 `and thus stops motor 92 from lifting the elevator, At this stage, the base of first or top layer of crates is about parallel to the slide plates 100, 100'.

The closi-ng of switch R5-2 closes the circuit via wire 321, switches LS12a, R1-3 and L53 to energize valve solenoids SVI, SVI'. These solenoids SV1, SVI open the valves of cylinders 111, 112 admitting air under pressure to drive piston rods 113, 114 toward each other, closing the slide plates 100, 100.

rAs the slide plates 100, 100' close, the tines 118 and 119 pass between adjacent bottles of the second topmost layer and engage the outer bottom edges of all crates in the top layer, urging these two lines of crates in the top layer together and upon further inward movement, lift the top layer of crates suiciently that the slide plates 100', 100' slide therebenath.

Upon the closing of both slide plates 100, 100 switches LS13 and LS14 spring open, thereby preventing the energization of relay M3 when the slide plates 100, 100 are closed.

When the slide plates 100, 100 are completely closed, they strike Iand close switches LS3 and LSIS, thereby making a circuit via wire 304 to energize relay M1 and thus actuate motor 140 to move the rakes 165, 165 across the closed slide plates 100, 100I urging the crates thereon, two at a time, over rollers 192, 192. As each pair of crates engages rollers 192, 192' they `are rapidly transferred `by rollers 192, 192' to rollers 180. Thus, in normal operation, there is -no need for the movement of rakes 165, 165 to be interrupted. The crates are deposited two `at a time on the live rollers 180 and are thence moved normal to -their path of discharge from the elevator chute, along rollers 180 and down the inclined ramp 199.

In FIG. 4 it will be seen that the switch LS2 is in a position to be engaged by the crates on the rollers 180. Since switch LS2 is essentially in alignment with standards 13C Iand 13d, the switch LS2 will be held open so long as crates on rollers 180 block the discharge of additional crates by the rakes 165, 165. Switch LS1 is in a position to be engaged and opened by crates being urged outwardly from the slide plates 100, 100 onto the rollers 180. Thus, whenever -there are crates in position to be Iacted upon by the rakes 165, 165 but there is no roorn on rollers 180 for furthe-r discharge, switches LS1 and L82 will be in open position, thereby interrupting current to relay M1 via wire 304.

It will be seen, therefore, that under normal conditions the fakes 165,\165 will be moved continuously because the forward crates will be rapidly removed by rollers 192, 192 as they are engaged. The rakes16'5, 165 will, how.- ever, be intermittently motivated by mot-or 140 in accordance with the .availability of space on rollers 180 for the discharge of crates thereto.

When the last pair of crates is discharged by the rakes 165, 165', switch LS1 will no longer be held open and hence closes. Thus the rake motor 140 will continue to rotate until the rake assembly completes its travel in a discharging direction. As the rake assembly reaches its extreme travel, lug 167 engages switches L84, LS4a, opening switch LS4a and closing switch L84. This breaks the circuit to relay M1 via wire 304 and makes thecirs cuit via wire 305, switch L84, switch LS5, switch M1-2 to relay M2, thereby reversing the rotation of motor 140. With the energization of relay M2, the hold-down switch M2-1 is closed, thereby permitting current to flow through the circuit to relay M2 even though switch 1.54 be subsequently opened. Thus the rakes 165, 165 continue their return travel until traveler 162 of the rake assembly engages switches LSS :and LSSa (mounted on brace 168 in FIGS. 5 and 6), opening switch LSS and closing switch LSSa and thereby interrupting current via wire 365 and switch L55. Thus, current to rake motor is interru-pted and the motor 140 stops.

It will be observed that during the time current is supplied via wire 305 past switch LS5 for the energirzation of relay M2 to return the rakes 165, 165', current is simultaneously supplied via wires 309 yand 310 to relay R3 and via wire 311, switches PE4, PBS and wire G13 to solenoids SVZ, SV2. The energization of solenoids SVZ, SVZ' actuates the valves of air cylinders 111, 112 and causes retraction of piston rods 113, 114, thereby again opening the slide plates 100, 100.

At this stage of the cycle of my machine, the elevator has moved up suflciently to clear switches L89, LS9a and LSS. Relays R2 and R4 thus drop out since switch LS9a closes after switch L88 opens, and thus the holddown switches R4-2 and R2-4 again open. IFurther, the deenergization of rel-ay R2 closes relay switch R2-3. Therefore, when the rake assembly closes switch .L-Sa and provided switches LS13 and H514 have been closed by the slide plates 100, 100' respectively, cur-rent is supplied to relay M3 and the hold-down switch M3-1 closes to shunt relay switch RZ-S. Thus, motor 92 is again started to raise the elevator until the top layer of crates engages 'and closes switch 1516 which energizes relay R5 and opens relay switch R5-1. The cycle, after the closing of switch L86, is therefore repeated Afor as many layers of crates as are stacked on the bottommost layer of crates.

It will be observed at this time that switch L88 is again open and relay R2 deenergized, switch R2-1 is open and the elevator may pass switch LS19 without danger of motor 49 being energized.

Since the tines 118, 119 cannot pass beneath the lowermost layer of crates without digging into the pallet itself, the removalof the last or bottomrnost layer is different from the preceding layers of crates. As the slide plates 100, 100 are opened, the rake assembly returns, and the elevator is moved upwardly containing only the bottommost layer of crates, the lpallet engages switches LS12, LSlZa, closing switch LS12 and opening switch LS12a. Thus, when the bottommost crates of bottles close switch L86 energizing relay R5, which closes switch R5-2, no current is supplied through wire 321 and the slide plates 100, 100' remain open. Since the closing of switch LS12 renders relay switch R5-1 ineliective, the elevator continues to travel upwardly until the pallet engages switch LS?, thereby energizing relay R1 via wire 224.

The energizing of relay R1 closes switch R1-1 of wire 316, opens switches R1-2 and R1-3 land closes switch R1-4. Thus, the circuit to relay M6 is broken stopping motor 92 from lifting the elevator and the circuit to relay M1 is made energizing the motor 140 which moves fakes 165, across the pallet, discharging the Vbottornmost layer from the pallet. Further, the circuit to solenoids SVI, SV1 is rendered inoperative by the opening of switch R1-3 and the circuit to relay M4 is rendered operative by closing of switch R1-1.

When the rakes 165, 165' begin their return travel, as a result lof the closing 'of switch L54, cur-rent is also supplied rvia wires 309, 310 to' relay R3. The energization of relay R3 closes switch R341 and hence a circuit is made vfrom bus 302. through switches R242, Rl-l, R21-1, via wire 316 and switch M1-1 to energize relay M4. Thus, motor 92 energized to move the elevator downl? lwandly. Upon the energization of relay M4, switch M42-l closes, thereby by-passing switches R1-1 and Ril-1 and the elevator continues its downward travel until it reaches the bottom and engage-s and closes switch L'SS. Relay R2 is thereby `again energized, closing switches RZ-l, R2- 3 `and R2-4 and opening switch R2-2. 'ihe opening of switch RZ-Z ideenergizes relay M4- and stops motor 9-2. The closing of switch RZ-Il ener-gizes relay M5 and starts motor 49 to drive `again the .infeed belts 22, 218 and 56 and chain 59. The closing of switch RZ-l energizes relay R4. Thus, the cycle, receiving and unloading the next loaded pallet, as hereinbefore described, is repeated.

As fthe next pallet is 'fed into the elevator chute, belts 56 discharge the unloaded pallet to chains S9 whence the unloaded pallet is carried into the pallet magazine where lever 21S .is engaged by the unloaded pallet and switch LS1() is closed. The closing of switch LSlll energizes v-ia wire 322 the solenoids SVS, SVS which actuate the valves of `air cylinders 202g, 29212 and thereby retract piston rods 26%, 203]).

The retracting of piston rods 26341, 203.5 causes skid plates 293m ESSI? to Ilift the unloaded pallet by its sides upwardly. The pallet moving upwardly acts against the camming members 224, 224- and continued upward travel of the pallet urges `the rocker arms 22M, 2216, 221e land ZZd outwardly until the pallet passes above the pallet engaging lingers 220', 2243" and the rocker arms 221:1, 221b, 221C and 21d pivot inwardly. l/Jhen the piston rods 2G31?, 2636 complete their upward travel delivering the unloaded pallet above lingers 2.2.0, 22S', lift beam 2li-fla strikes `and closes switch LSH (of HG. 7) and this energizes via wire 323, the solenoids SV4, SVd which change .the valves `of the air cylinders 292g, 29219 to return the piston rods 293:1, 29315 to their original eX- tended posit-ions.

It lwill now be seen that the operation, above described, continues with an additional loaded pallet being fed to the elevator as the preceeding pallet is simultaneously fed to the pallet magazine from the elevator. The unloaded pallet is thereafter lifted beyond the lingers 229, 22S' to become the lbottomniost pallet in the pallet magazine and support the pallets in the pallet magazine thereabove.

When the pallet magazine is lilled, the uppermost pallet engages switch LSZS which opens the circuit to relay M5 and prevents the energizing of motor 49 for the feeding of additional pallets to either the elevator or the pallet magazine. Thereafter a lift truck may remove the stacked pallets from the pallet magazine.

lt will be 'observed that l have provided a number of safety features in my machine. For example, the overheating of any of the motors will cause the interruption of current to all circuits `through the opening of any one of switches MSE, MS2, M83 or M84. The interruption of current either by the blowing of `fuse F or the opening of one of switches M51, MS2, MSS or M84 wl be indicated by light GL going out. Further, current cannot be supplied to relays Ml and M2 simultaneously since the energization of relay M2 will open switch MZ-Z. Also, relays M3 and M4 cannot be energized simultaneously since the energization of relay M3 lopens switch M3-3 `and the energization roi relay M4 opens switch M4-2.. Switch LS'l9 is placed with-in the elevator chute to detect the presence of a loaded pallet and prevents actuation of motor 49.

ln the event the rakes 165, 65 `do not completely return, the depressing of switch PB?. will supply current -to enengize relay M2 and start motor Mil' to cause travel of -the rakes 165, 16S' in a return direction until the rake assembly opens switch LSS.

A better understanding of my invention may be had by reference to the table below which outlines the dunction or" the various switches:

l S Unloader Control System Function In parallel with LS-2 stops rake if cases in both positions. In parallel with LS-l stops rake if cases in both positions. 1]@ 3 {(1) Starts rake forward when plates are closed. u `(2) Shuts od power to plate forward circuit.

(ig ltp ratke forward circu.) t t 1 t t (2 a sarsrakereurn; sarspaereurn LSA LS-fla circuit; (c) euergizcs R-3 relay which starts elevator down when pallet is empty. {(1) Stops rake on return.

(2) Stops elevator up circuit until rake is returned. {(l) Operates R-5 which (a) stops olcvator up circuit Ls-5, Ls-sa in parallel with LS-12 for 6% ox. bottles; (b) starts plate forward circuit for 6% ox. bottles.

(2) shuts ofi power to relay R-2.

Encrgizcs R-l Relay.

(1) Stops elevator up.

(2) Makes part of elevator down circuit.

(3) Stops plate forward circuit when elevator all the way up.

(4) Starts rake forward circuit.

Energizcs R-Z Relay.

(l) Starts ramp motor.

(2) Stops elevator down.

(3) Holds elevator up circuit closed when elevator oil LS-S.

Starts elevator up.

Starts pallet magazine Air Cylinder.

Pallet air cylinder retract.

Holds elevator up Circuit in parallel with relay R-5 to raise last layer of cases high enough to rake directly from pallet.

Stops elevator from coming up when plates are not fully returned.

Positions elevator and starts plate forward circuit for 10 and 12 oz. bottles (Same as LS-).

In parallel with LS-l7 and stops rake if cases open switch LS-l and LS-l7.

In parallel with LS-16 and stops rake if cases open switches LS-lG and LS-l7.

Starts rake forward when plates are closed. Pallet infeed safety. A Turns oil' machine when pallet magazine is full.

LS-G

Ls-s, Ls-sa IAS-9, LS-Ga LS-13, LS-ll -It will be obvious toithose skilled in the art that many variations may Ibe 'made in the embodiment chosen for 'che purpose of illustrating the present invention, elements may be combined las separated into several parts `and full resort may be had to the use of equivalents without departing rfrom the scope of my invention as defined by the appended claims.

-I claim:

l. An unstaclsing machine comprising an elevator chute, an elevator vertically moveable in said chute, infeed conveyor means for feeding pallets loaded -Wi-th layers of articles thereon successively to said elevator chute `and over said elevator, means for preventing the travel of said pallets to said elevator chute when said elevator has received a loaded pallet, means yfor preventing the travel of said pallets to said elevator until said elevator is positioned in its lowermost position, means for spacing said pallets on said infeed conveyor, a pair of opposed horizontally disposed slide plates operably associated with said elevator chute and moveable toward each other across said elevator chute, downwardly and inwardly projecting tines iat the iner edges of said slide pla-tes for urging the topmost layer of articles upwardly las said slide plates move toward each other, means 4for reciprocating said slide plates in timed relationship to the movement of said elevator, reciprocatable rake means moveable across said slide pla-tes tor pushing articles from said slide plates, and a discharge conveyor opposite said rake means for receiving articles pushed by said rake means and `for :arranging said articles in single lile fashion upon being received thereon.

2. ln a machine for unloading a plurality of horizontal layers of articles arranged in stacked layer formation on a pallet, each layer being formed of a plurality of side-byside rows of articles, a conveyor for receiving and carrying a pallet loaded with the stacked layers of articles, an elevator within said lunloading station for receiving said loaded pallet from said conveyor `and for raising said pallet step-by-step upwardly by distances approximately equal to the height of said layers, :slide plate means disposed at said unloading station and above said elevator for movement between the uppermost layer and the layer therebeneath to successively remove and receive thereon the uppermost layer after each -step of movemen-t upwardly of said elevator, article engaging means on said slide plate means and moveable therewith for progressively engaging the sides of the articles in said uppermost layer and for urging said articles in said uppermost layer upwardly away vfrom the layer of articles -therebelow and onto said slide plate means as said slide plate means is moved between said uppermost layer and the layer Itherebene-ath, means disposed at said unloading station for discharging row by row the layer of larticles `from said slide plate means, and conveyor means positioned adjacent said slide plate means for receiving each row of articles as it is discharged from said slide plate means and for arranging and discharging the articles in single tile fashion.

3. In 'a machine -for unloading a plurality of horizontal layers of articles arranged in stacked layer formation on a pallet, each layer being formed of a plurality of side-byside rows of articles, a conveyor extending into an unloading station for receiving and carrying a pallet loaded with the stacked layers of articles, an elevator within said unloading station for receiving said loaded pallet and for raising said pallet step-by-step upwardly by distances approximately equal to the sheiglit of said layers, slide plate means disposed at said unloading station :and above said elevator for movement between the uppermost layer and the layer therebeneath to successively remove and receive thereon the uppermost layer after each step of movement upwardly of said elevator, article engaging means on the end of said slide plate means for engaging the articles in said uppermost layer as said slide plate means is moved and for urging said articles onto said slide plate means, means disposed at said unloading station for discharging row by row the layer of articles fromsaid slide plate means, and a conveyor positioned adjacent said slide plate means for receiving each row of articles as it is discharged from said slide plate means and for arranging and conveying the articles in single iile fashion.

4. In a machine for unloading a plurality of horizontal layers of articles arranged in stacked layer formation on a pallet, each layer being formed of a plurality of side-bys-ide rows of articles, a conveyor extending into an unloading station for receiving and carrying a pallet loaded with the stacked layers of articles, an elevator within said unloading station for receiving said loaded plallet and for raising said pallet step-by-step upwardly by distances approximately equal to the height of said layers, slide plate means disposed at said unloading station and above said elevator for movement between the uppermost layer and the layer therebeneath to remove and receive thereon the upper-most layer after each step of movement upwardly of said elevator, rake means disposed at said unloading station and above said slide plate means, means for moving the rake .means across the slide plate means for discharging row by row the layer of articles trom said slide plate means, and la conveyor positioned adjacent said slide plate means for receiving each row of articles as it is discharged from said slide plate means and for arranging and conveying the articles in single tile fashion.

5. In a machine for unloading a plurality of horizontal layers of articles arranged in stacked layer formation o-n a pallet, each layer being formed of a plurality of side-byside rows of articles, a conveyor extending into an unloa ing station for receiving and carrying a pallet loaded with the stacked layers of articles, an elevator within said unloading station for receiving said loaded pallet and for raising said pallet step-by-step upwardly by distances approximately equal -to the height of said layers, a pair of opposed slide pla-tes disposed -at said unloading station and above said eleva-tor Vfor movement toward each other and away from each other, said slide pla-tes when moved toward each other extending between the uppermost layer and the layer therebeneath to successively remove and receive thereon the uppermost layer after each step of E@ movement upwardly of said elevator, rake means disposed at said unloading station and above said slide plates, meians for moving the rake means across the slide plates for discharging row by row the layer of articles fromV said slide plates, and a means positioned adjacent said slide plates for receiving each row of articles as it is discharged from said slide plates and 4for arnangin-g and discharging the articles in single tile fashion.

6. in a machine for unloading a plurality of horizontal layers of articles arranged in stacked layer formation on a pallet, each layer being formed of a plurality of sideby-side rows of `artic-les, a conveyor extending into an unloading strati-on for receiving and carrying a pallet loaded with the staclced layers of articles, an elevator within said unloading station for receiving said loaded pallet and for raising said pallet step-by-step upwardly by distances approximately equal to lthe height of said layers, a pair of opposed slide plates disposed in a common transverse plane at said unloading station and above said elevator for movement toward `each other and between the uppermost layer and the layer therebeneath to remove and receive thereon the uppermost layer after each step of movement upwardly of said elevator, article engaging means on said slide plates for engaging the articles in said uppermost layer as said slide plates are moved and for urging said articles onto said slide plates, rake means disposed at said unloading station and above said slide plates, means for moving the rake means across the slide plates after said slide plates have been moved toward each other for discharging row by ro-w the layer of articles from said slide pla es, and a conveyor positioned adjacent said slide plates for receiving each row of articles as it is discharged from said slide plates and for afhanging and conveying the articles in single iile fashion.

7. `l'n -a machine of the class having an upright frame defining an upright unloading station wherein a plurali-ty of horizontal layers of articles arranged in stacked layer formation on a pallet are unloaded, each layer being formed of a plurality of side-by-side rows of articles, a conveyor extending into said unloading station for receiving and carrying a pallet loaded with the stacked layers of articles, an elevator within said unloading station for receiving said loaded pallet and for raising said pallet step-by-step upwardly by distances approximately equal to the height of said layers, a pair of opposed slide plates carnied by said frame in a common transverse plane above said elevator for movement between the uppermost layer and the layer beneath to successively remove and receive thereon the uppermost layer after each step of movement upwardly of said elevator, rake means disposed at said unloading station 'and above said slide plates, means for moving the rake means across the slide plates for `discharging row by row the layer of articles from said slide plates, and a conveyor positioned adjacent said slide plates for receiving each row of articles `as is is discharged from said slide plates and for arranging and conveying the articles in single tile fashion.

8. In Ia machine for unloading a plurality of horizontal layers of articles arranged in stacked layer formation on a pallet, each layer being formed of a plurality of sideby-side rows of articles, a conveyor extending into an unloading station for receiving and carrying a pallet loaded with the stacked layers of articles, lan elevator within -said unloading station for receiving said loaded pallet Vand for raising said pallet step-by-step upwardly by distances approximately equal to the height of said layers, slide plate means disposed at said unloading station and above said elevator for movement between the uppermost layer and the layer beneath to successively remove and receive thereon the uppermost layer after each step of movement upwardly of said elevator, control nieans 4for detecting when said slide plate means has been moved beneath said uppermost layer, rake means disposed at said unloading station and above said slide plate means, drive means controlled by said control means for moving the rake means yacross the slide plate means for discharging row by row the layer of articles from said slide plate means, la conveyor positioned adjacent said slide plate means for receiving each row of articles as it lis discharged from said slide plate means and for arranging and conveying the `articles in single le fashion and means for detecting |when Iarticles are received `on said last mentioned conveyor for interrupting the yaction of said drive means until the articles have been conveyed by said last mentioned conveyor.

9. ,-In a machine for Unloading a plurali-ty of horizontal layers tof articles arranged in stacked layer formation on a pallet, each layer being formed of a plurality "of side-by-side rows of articles, a conveyor extending into an unloading station for receiving and carrying `a pallet loaded with the stacked ,layers of articles, an elevator within said unloading station for receiving said loaded pallet yand for raising said pallet step-by-step upwardly by distances yapproximately equal to the height of said layers, slide plate means disposed at said unloading station 'and above said elevator for movement between `the uppermost layer land the layer therebeneath to successively remove and receive thereon the uppermost layer after each step of movement upwardly of said elevator, article en- `gaging means protruding inwardly from the end of said slide plate means and extending below the upper surface of said slide plate means for progressively engaging the articles in said uppermost layer as said slide plate means is moved and for urging said articles upwardly onto the upper surface of said slide plate mean-s, means disposed Iat said unloading station for discharging row by row the layer fof articles from said slide plate means, and a conveyor positioned adjacent said slide plate means for receiving each row of articles as it is discharged from said slide .plate means and for arranging and conveying the articles `in single iile fashion.

References Cited in the le of this patent UNITED STATES PATENTS 1,464,513 Sutherland Aug. 14, 1923 1,772,734 Romine Aug. 12, 1930 2,609,109l Ardell Sept. 2, 1952 2,643,009 Kenyon June 23, 1953 2,727,642 Haycock Dec. 201, 1955 2,729,344 Birchall Jan. 3, 1956 2,741,379 Stryker Apr. 10, 1956 2,774,489 Guigas Dec. 18, 1956 2,792,950 Fenton May 21, 1957 2,815,870 Laub Dec. \10, 1957 2,902,182 Thomas Sept. 1, 1959 2,956,697 Madden Oct. 18, 1960 2,994,444 Peterson Aug. 1, 1961 

1. AN UNSTACKING MACHINE COMPRISING AN ELEVATOR CHUTE, AN ELEVATOR VERTICALLY MOVEABLE IN SAID CHUTE, INFEED CONVEYOR MEANS FOR FEEDING PALLETS LOADED WITH LAYERS OF ARTICLES THEREON SUCCESSIVELY TO SAID ELEVATOR CHUTE AND OVER SAID ELEVATOR, MEANS FOR PREVENTING THE TRAVEL OF SAID PALLETS TO SAID ELEVATOR CHUTE WHEN SAID ELEVATOR HAS RECEIVED A LOADED PALLET, MEANS FOR PREVENTING THE TRAVEL OF SAID PALLETS TO SAID ELEVATOR UNTIL SAID ELEVATOR IS POSITIONED IN ITS LOWERMOST POSITION, MEANS FOR SPACING SAID PALLETS ON SAID INFEED CONVEYOR, A PAIR OF OPPOSED HORIZONTALLY DISPOSED SLIDE PLATES OPERABLY ASSOCIATED WITH SAID ELEVATOR CHUTE AND MOVEABLE TOWARD EACH OTHER ACROSS SAID ELEVATOR CHUTE, DOWNWARDLY AND INWARDLY PROJECTING TINES AT THE INNER EDGES OF SAID SLIDE PLATES FOR URGING THE TOPMOST LAYER OF ARTICLES UPWARDLY AS SAID SLIDE PLATES MOVE TOWARD EACH OTHER, MEANS FOR RECIPROCATING SAID SLIDE PLATES IN TIMED RELATIONSHIP TO THE MOVEMENT OF SAID ELEVATOR, RECIPROCATABLE RAKE MEANS MOVEABLE ACROSS SAID SLIDE PLATES FOR PUSHING ARTICLES FROM SAID SLIDE PLATES, AND A DISCHARGE CONVEYOR OPPOSITE SAID RAKE MEANS FOR RECEIVING ARTICLES PUSHED BY SAID RAKE MEANS AND FOR ARRANGING SAID ARTICLES IN SINGLE FILE FASHION UPON BEING RECEIVED THEREON. 